Fig. 7

Schematic diagram. A schematic diagram of the role of ROS-FOXC1-cysteine-ROS positive feedback loop in HCC proliferation and metastasis. ROS upregulates FOXC1 expression through the ERK1/2-p-ELK1 signaling pathway. High-expression of FOXC1 induced the DNA hypermethylation of CTH promoter and CTH gene silencing through upregulating DNMT3B expression, which resulted in the decrease of cysteine levels and increases of ROS levels. The antioxidant NAC inhibits ROS-mediated FOXC1 upregulation, thereby inhibiting ROS-FOXC1-cysteine-ROS signaling-mediated HCC proliferation, migration and invasion